INFLUENCE OF TROPICAL ATLANTIC SUBREGION ON THE PRECIPITATION IN EASTERN OF NORTHEAST BRAZIL
Climatic Environment, Cluster Analysis, Linear Regression, Principal Components.
At this study identified the influence of Sea Surface Temperature (SST) similar of the Tropical Atlantic Ocean in the north east of Northeast Brazil (NLNEB) precipitation. Hydrometeorological network of the Agência Nacional de Águas (ANA) validate a product of the University of Delaware covering the 1900 to 2008 period. Were used monthly SST data from NOAA - Extended Reconstructed Sea Surface Temperature V3B (NOAA_ERSST_V3) for areas of the Atlantic and the Pacific between 40ºN and 40ºS latitudes. We consider three large-scale environment: presence of El Niño in the Pacific and the positive difference between SST anomalies on the Northern (5-20 ° N, 60-30 ° W) and South (0-20 ° S, 30 ° W -10 ° E) areas of the Tropical Atlantic Ocean (unfavorable environment); presence of La Niña in the Pacific and negative difference between the SST anomalies on the Northern (5-20 ° N, 60-30 ° W) and South (0-20 ° S, 30 ° W-10 ° E) areas of the Tropical Atlantic Ocean (favorable environment); absence of El Niño and La Niña, as well as the absence of SST anomalies on the Northern areas (5-20 ° N, 60-30 ° W) and South (0-20 ° S, 30 ° W-10 ° E) Atlantic Tropical (Neutral environment).The cluster analysis was applied to the SST monthly data at each grid point at the three climatic environment of the Atlantic Ocean. Euclidean distance was used as similarity (dissimilarity) measurement, the Ward's Minimum Variance agglomerative Method as connection method and Silheuta graphic was used to assess the partition in each group. Were identified clusters six at each climatic environment. Student-t test identified subgroups four with significant differences in the SST averages between FAV / DESFAV and neutral environment. The multiple linear regression (MLR) by principal components was used to verify the groups potential prediction in the NLNEB precipitation. The ocean-atmosphere interaction revealed FAV environment groups with potential prediction for the NLNEB precipitation, the areas of the DESFAV environment not statistically significant (p-value <0.05) in the NLNEB precipitation.